An American naturopathic physician, Peter J. D'Adamo has made his name writing about the controversial blood type diet, which proposes that appropriate diet and lifestyle depends on an individual's blood type.

Peter J. D'Adamo holds Naturopathic Doctorate (ND), and bases his theories on the work of his father, James D'Adamo, who wrote the first books on the concept of blood group and diet.

Peter J. D'Adamo co-authored his books with health writer Catherine Whitney, and they have found a core of faithful adherents, even though the blood type diet is neither popular nor accepted among the majority of physicians, naturopathic or otherwise.

The original idea has been parlayed into a vast range of titles including:

Eat Right 4 Your Type.
Cook Right 4 Your Type.
Live Right 4 Your Type.
The Complete Blood Type Encyclopedia.
Eat Right 4 Your Baby.
Cancer: Fight it with the blood type diet.
Diabetes: Fight it with the blood type diet.
Arthritis: Fight it with the blood type diet.
Cardiovascular Disease: Fight it with the blood type diet.
Allergies: Fight them with the blood type diet.
Fatigue: Fight it with the blood type diet.
Menopause: Manage its symptoms with Blood Type Diet.
Aging: Fight it with Blood Type Diet.